verb (v)

• provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes(verb.communication)

  Synonym:
  attest, demonstrate, evidence, manifest
  

  source: wordnet30
• guarantee payment on; of checks(verb.possession)

  source: wordnet30
• authorize officially(verb.social)

  Synonym:
  licence, license
  Antonym:
  decertify, derecognise, derecognize
  

  source: wordnet30
• guarantee as meeting a certain standard(verb.social)

  Synonym:
  endorse, indorse
  

  source: wordnet30
• declare legally insane(verb.communication)

  source: wordnet30
• To give cetain information to; to assure; to make certain.(verb)

  source: webster1913